Has anyone noticed that after 20 years and $25 billion in government-sponsored research on climate change, the political controversy over global warming is actually more intractable and bitter today than it has ever been in the past?
A dangerous idea has taken hold in modern politics, and the sooner it is discredited, the better. The idea is that political disagreements can be resolved by science. Its basic logic seems sensible: As good children of the Enlightenment, we should turn to science to establish the facts about problems such as climate change before deciding what policies to implement. Yet the types of things that scientists are good at figuring out don't have much to do with the types of things that politicians need to decide.
If this point seems seditiously antirational, consider the recent history of environmental politics in the United States. In the late 1960s and early 1970s, Congress enacted an impressive raft of laws addressing air and water quality, endangered species, pesticide use, toxic waste cleanup, and the environmental impacts of government projects.
The state of scientific knowledge at that time was primitive relative to today. But the political climate was favorable, and many of the problems — like smog and burning rivers — were obvious for all to see, so the science was more than sufficient to support action. Laws were passed, regulations were promulgated, and environmental protection was advanced.
Four decades later, scientific understanding of the environment has improved immeasurably, while political action has become almost impossible. More knowledge has created more uncertainty about what works and what doesn't.
When people hold strongly conflicting values, interests and beliefs, there is not much that science can do to compel action. Indeed, more research and more facts often make a conflict worse by providing support to competing sides in the debate.
Writing in the New York Times recently, Al Gore noted that "the science has become clearer and clearer." Yes, there is a robust scientific consensus that human activity is causing the atmosphere to warm up. So? Decisionmakers need to know how climate change will affect specific political jurisdictions and, more importantly, what types of interventions will make a difference, over what time scales, at what costs, and to whose benefit — and whose detriment.
When it comes to questions like these, political beliefs can map nicely onto different ways of selecting and interpreting the science. If you believe that government should intervene in markets to incentivize rapid reduction of greenhouse gas emissions, you can justify your preference with data and models that predict increases in extreme weather events such as hurricanes, droughts and floods.
And if you believe, as do many conservatives, that government intervention in markets and in social arrangements should be kept to a minimum, you can find factual support for your views in the long-term unpredictability of regional climate behavior, the significant economic and social costs associated with shifting to more expensive energy sources, and the historical failure of government efforts to steer large-scale social and economic change.
Politics isn't about maximizing rationality, it's about finding compromises that enough people can live with to allow society to take steps in the right direction. Contrary to all our modern instincts, then, political progress on climate change requires not more scientific input into politics, but less. Value disputes that are hidden behind the scientific claims and counterclaims need to be flushed out and brought into the sunlight of democratic deliberation. Until that happens, the political system will remain in gridlock, and everyone will be convinced that they are on the side of truth.
Daniel Sarewitz co-directs the Consortium for Science, Policy and Outcomes at Arizona State University.